单项选择题
A.easy access to its storage compartment
B.replacement of the battery without exposure to the weather
C.it to float free if the unit sinks
D.it to remain attached to the unit
单项选择题 Each drilling unit equipped with helicopter fuel storage tanks must have the tanks installed as far as practicable from the（）.
单项选择题 During which condition should the operator of a pedestal crane shutdown operations?（）
单项选择题 During which condition should the operator of a pedestal crane shutdown operations?（）